Ответ:\(38+x=84\), \(x=84-38=46\).\(x\cdot18=72\), \(x=72:18=4\).\(x-24=56\), \(x=56+24=80\).\(x:16=6\), \(x=6\cdot16=96\).\(x\cdot13=91\), \(x=91:13=7\).\(21-x=15\), \(x=21-15=6\).Ответ: 46; 4; 80; 96; 7; 6.